4. First, let's change all of the mixed fractions into improper fractions.
3 5/6 - 1 4/5 = 23/6 - 9/5
We can't subtract yet since the denominators aren't equal, so we have to find a common multiple, which is 30.
23*5/6*5 - 9*6/5*6 = 115/30 - 54/30 = 61/30
5. For this question, it might be easier to convert the fractions into decimal.
Marty weighs 64.25 pounds, and Nathan weighs 76.5
76.5-64.25 = 12.25
Nathan weighs 12.25 more pounds.
